Charlotte Crellin was last seen in the area of Jefferson Road on 30 June 2019 at around 11pm.
Since then officers have conducted numerous enquiries to locate her, including reviewing CCTV and conducting area searches.
Ms Crellin is described as being around 5ft 3ins tall with a slim build and long, brown hair.
The 24-year-old was last seen wearing a denim jumpsuit with a white short-sleeved shirt and white plimsoles. She was also carrying a black leather shoulder bag.
Anyone with information is asked to call Kent Police on 101 quoting 30-1425.